It is common in the prior art to construct temporary protective enclosures. Such prior art enclosures or structures are constructed generally in a similar manner to more permanent structures. Typically, the framework is nailed together and covered with a material such as plywood, corrugated steel, plastics or composite materials in sheet form. The covering is also nailed or bolted to the framework. Typically, such shelters provide temporary protective enclosures for equipment and materials to be used at a work site. Erection and disassembly of such structures is time consuming and expensive. Applications of such prior art enclosures include: utility storage shelters, equipment shelters and temporary warehouses. When such prior art structures are to be used to seal out airborne contaminant particles additional complex and expensive sealing materials are required to provide a protective enclosure. With the present requirements that hazardous materials such as asbestos be removed from existing structures, there is a great need to provide temporary protective enclosures, which can be quickly and easily erected at the site by unskilled persons, which is substantially imprevious to contaminants, and which can be easily disassembled and removed.
While the availability of transparent and translucent forms of synthetic plastic sheet materials such as polyvinylchloride and polyethylene, provide suitable covering material for protection against contaminants such as asbestos, there still exists a need to provide a low cost skeletal frame structure which is easily erected and disassembled with a minimum of inexpensive materials.
Accordingly it is a desirable object of the present invention to provide a device for forming joints to permit the fabrication of simple, low cost enclosure frames.
Another desirable object of the present invention is to provide a skeletal frame structure that can be easily erected and disassembled by an unskilled person.
A still further desirable object of the present invention is to provide a shelter frame that can be fabricated in a wide range of sizes.
It is yet a further desirable object of the present invention to provide a joint forming device which permits the fabrication of enclosure frames suitable for covering with synthetic plastic sheet material.
A still further desirable object of the present invention is to provide a temporary protective enclosure which is easily erected and disassembled.
The above and other desired objects, apparent from the drawings and following description, may be attained by the apparatus, construction, arrangements and combinations, subcombinations, and parts which comprise the present invention, preferred embodiments of which are illustrative of the mode in which applicant has contemplated applying the principal, being set forth in detail in the following description and illustrated in the accompanying drawings.